<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    * {
      margin: 0;
      padding: 0;
    }

    .box {
      width: 600px;
      height: 600px;
      background-color: pink;
      /* 
      grid布局是一种网格布局
      */
      display: grid;
      grid-template-columns: repeat(3, 100px);
      grid-template-rows: repeat(3, 100px);
      /* 设置行间距 row-gap */
      /* row-gap: 10px; */
      /* 设置列间距 column-gap */
      /* column-gap: 10px; */
      /* 总写法：+
      ga'pgap 行 列 */
      gap: 10px 20px;
      /* 合并单元格 */
    }

    .item {
      background-color: skyblue;
      border: 1px solid aqua;
    }
  </style>
</head>

<body>
  <div class="box">
    <div class="item">1</div>
    <div class="item">2</div>
    <div class="item">3</div>
    <div class="item">4</div>
    <div class="item">5</div>
    <div class="item">6</div>
    <div class="item">7</div>
    <div class="item">8</div>
    <div class="item">9</div>
  </div>
</body>

</html>